Cylindrical article



March 1960 F. c. STEVENS 2,930,408

CYLINDRICAL ARTICLE Filed June 28, 1957 IN V EN TOR.

BY $44M awn/leg United States Patent F 2,930,408 CYLINDRICAL ARTICLE Fred C. Stevens, Maywood, lll., assignor to The Richardson Company, Melrose Park, Ill., a corporation of Ohio Application June 28, 1957, Serial No. 668,691

4 Claims. (Cl. 138-78) This invention relates to tubular articles and in particular to articles of the type which may be readily severed into shorter lengths.

At present there is a demand for means to carry various materials in the form of a large package with provision for subdividing the package so as to provide smaller predetermined quantities of the material without destroying or otherwise affecting the remaining contents of the package. For example, in the field of explosives it is sometimes desirable to provide a package containing a rather large amount of explosive which can be severed so as to make available a smaller given amount of explosive for a particular use. In addition, there is a demand for housings for rocket propellents whereby a portion of the housing can be broken away as the rocket is advanced in flight. Uses such as the foregoing have resulted in more attention being given to packages and housings which can be subdivided at predetermined points.

Accordingly, it is one object of this invention to provide a tube which may be severed at predetermined areas for the purpose of forming smaller tubes of a given length or for the purpose of removing a portion of the tube from the remainder of the tube.

Another object of the invention is to provide a tube of the foregoing type which can be made inexpensively and whose manufacture will lend itself to the use of pres ent day practices employed in the broadly analogous laminating art.

These and other objects of the invention will become more apparent by reference to the following specification and attached drawing.

In the drawing, Figure l is a prospective view of a tube contemplated by this invention.

Figure 2 is a cross section of the tube.

In brief the invention involves forming a plurality of small tubes, assembling the tubes in end to end relationship and covering the assembly with an outer overall covering, thereby forming an integral article. Under a predetermined force, depending on the thickness of the outer covering, the composite large tube can be broken into small lengths along the circumferential line established by the smaller internally disposed tubes at the points where their ends abut one another.

Turning now to the drawings, the numeral indicates generally a tube of the type contemplated by this invention, the same being severable, under a predetermined force, along the dotted lines 12, which lines are actually the areas of abutment of the smaller internal tubes 13. The outer covering 14 extends for the full length of the tube.

In making a structure of the foregoing type, the smaller tube sections 13, are first formed, preferably by wrapping a sheet of fibrous material, impregnated with a resin, about a mandrel, followed by curing the wrapping on 2,930,408 Patented Mar. 29, 1960 the mandrel in an oven. Small individual tubes can thus be made, or, alternately, a larger tube first formed and then cut into smaller segments of the desired length.

Various fiber sheets and resins can be employed to form the tubes. Fibrous fillers such as paper or other cellulosic materials can be used as can fabrics formed from either naturally occurring or synthetic fibers, including fibers made from glass. With respect to the resins which are used to impregnate the filler, resins such as those used in the laminating art can be readily employed but should be preferably those resins that are thermosetting, although for certain application thermoplastic resin will be adequate. Particularly suitable are phenolic resins formed by reacting phenol, cresol, xylenol, or mixtures thereof with formaldehyde.

After the individual small tubes 13 have been made they can then be disposed on a large mandrel and held firmly in end to end relationship while the outer covering 14 is applied.

The outer covering may likewise be formed from filler sheet of fibrous materials impregnated with similar resins, preferably thermosetting, which will cure to a hard condition.

When thermosetting resins are used in forming the small individual tubes 13, as indicated above, the curing may be such that the resin is cured to a final hardened state or to a state which is somewhat less than the final cure. If the latter process is used wherein there is less than a final cure, the curing conditions employed to cure the outer wrapping will result in more intermingling between the resins of the outer wrapping and those used in forming the small tube 13 whereby a more integral product will be formed, especially if the two resins used are the same.

The outer covering 14 is, preferably, wound convolutely and it can be seen that the force needed to break away one or more individual tube sections from the remainder of the tube will be, for the most part, determined by the number of windings on outer cover 14. Thus, if only one or two outer convolute windings are employed, a relatively small force may be used in breaking off a section of the tube, whereas if seven or eight windings are used a greatly increased force will be necessary to sever a section.

Tubes or housings may be made for a variety of uses, depending on length of the sections believed necessary and the amount of force required to break away a section. Although it has been indicated that convolute windings be used in forming the tubes of this invention, it is possible that similar structures can be formed by using helical windings.

While I have disclosed certain embodiments of the invention, the same is only intending to be limited by the scope of the following claims.

I claim:

1. A rigid, hollow cylindrical article having circumferentially weakened areas at predetermined points along its length whereby said article may be subdivided into shorter lengths comprising a plurality of independent inner tubes disposed end to end, each of said inner tubes being composed of a convolutely wound fibrous sheet impregnated with a cured thermosetting resin, a longitudinally continuous outer covering convolutely wound about said inner tubes, said outer covering being composed of a fibrous sheet impregnated with a cured thermosetting resin, said inner tubes being permanently united to said longitudinally continuous outer covering thereby forming an integral assembly.

2. A cylindrical article as described in claim 1 wherein said thermosetting resins are selected from the class consisting of the reaction product of formaldehyde with a phenol, cresol, xylenol and mixtures thereof.

3'. A cylindrical article as described in claim 2 wherein the fibrous sheet is paper.

4. A cylindrical article as described in claim 1 wherein the same thermosetting resins are used in forming the individual tubes and the continuous covering.

UNITED STATES PATENTS Nordlinger Dec. 19, 1899 Vogt May 14, 1935 Trevellyan Oct. 13, 1936 Blum Apr. 27, 1937 Caldwell June 11, 1957 

